These days, most people carry a cell phone with them everywhere they go: to work, to church, on vacation, and more. And cell phone carriers may capture and retain records of your location even when you’re not using your phone. Does that mean that the government can simply demand these records from your carrier without a warrant? Unfortunately, according to Judge Royce Lamberth of the D.C. District Court, the answer to that question is ‘yes.’

Judge Lamberth wrote [pdf] that a "reasonable cellular phone customer presumably realizes that his calls are all transmitted by nearby cell-site towers, and that cellular phone companies have access to and likely store data regarding the cell-site towers used to place a customer's calls," and a person's "decision to place a cellular phone call and thus provide information regarding his location to the phone company thus defeats an individual's privacy interest in that information." But both of these assertions are flawed. People (including some members of Congress) were taken by surprise earlier this year when researchers announced that the iPhone was retaining a log of location information derived from cell towers. And using a cell phone, even if you know that the phone company has access to your location, shouldn’t mean that the government has a right to access this sensitive information about who you are and where you go without going to a judge and getting a warrant. That’s especially true when your carrier knows where you phone is any time it’s turned on (even if you’re not actively using it) and retains this information for longer than you might expect.

Unfortunately, we know that law enforcement is taking advantage of outdated privacy protections to demand your location history from your cell carrier without a warrant. What we don’t know is how often this happens — yet. But we’re engaged in a nationwide campaign to demand information about this practice so we can understand how and why law enforcement officials in various states are demanding Americans’ location histories — and whether they are getting a warrant first. (Want to know what’s happening in your state? Find out here!)

ECPA is marking its 25th birthday next week, but unfortunately it hasn’t really grown up at all since then. So please join us in telling Congress that it’s time to update ECPA and provide modern privacy protections to match today’s technology.